What is GeoPS?

Thermodynamic phase equilibrium modeling paves the way toward a quantitative understanding of geological processes such as metamorphism and magmatism. It can forward simulate the metamorphic or magmatic system, to predict the stable mineral assemblages, compositions and various physical and chemical properties of given P-T conditions. Phase equilibrium modeling also has been a very important method to determine the metamorphic P-T condition and evolution path of rocks.

GeoPS is a free visual phase equilibrium simulating software, which is based on Gibbs free energy minimum method.

It provides a wide range of phase equilibria calculations and illustration facilities, including calculation of various types of phase diagrams (P-T, P-X, T-X, X-X), isopleths, and thermodynamic modelling for path-dependent open system processes. And more functions are being developed.

What you see is what you get. The friendly GUI and no cost of learning make thermodynamic modelling accessible to any researchers and students of earth sciences.

Super-high efficiency makes you can get the results while you wait, even for modelling a complex system.

How Fast?

Well-designed architecture and data structures, efficient algorithms make exceptional computing efficiency. It needs only a few minutes to complete a complex phase diagram. To quantitate the speed, the following table compares the performance of three different software in the same test platform.

Test platform：

A: Dell XPS-15 Laptop，CPU i7-6700HQ 2.6GHz, 16G RAM， Windows10 ×64 Home

B: Lenovo ThinkCentre M8300 Desktop，CPU i7-2600 @3,4Hz, 16G RAM， Windows10 pro ×64

Fig.	GeoPS 1 thread ^a	GeoPS 1 thread^b	GeoPS 4 threads^b	Perple_X v6.8.6	Domino	Note
BL487 Green 2016 Fig.4a	8m30s; Pre:<1m	6m29s; Pre:<1m	3m25s Pre：<30s	~17h	2h57m	In Perple_X, initial_resolution=[1/8 1/16], the rest of options are default. See results
White 2014 Fig.9a	17m25s; Pre:<1m	13m16s; Pre:~40s	4m8s Pre：<30s	1h23m	1h31m22.34s	In Perple_X, initial_resolution=[1/10 1/20], the rest of options are default. See results
KLB-1 J&H 2015 Fig.1	8m01s; Pre:<1m	5m30s; Pre:~30s	1m51s Pre：<20s
BL487 Without solutions	22s; Pre:3s	21s; Pre:2s	20s Pre：<3s	2s		Perple_X default options。 See results

  a：computer A；
  b： computer B；
  Pre: Preliminary result；
  For Perple_X and Theriak-Domino, the time is only computation time, not include creating diagram；The time of GeoPS include computing and drawing.
  Theriak-Domino, using the version of D.K. Tinkham，from： http://dtinkham.net/peq.html 
  Perple_X v6.8.6， from official website：http://www.perplex.ethz.ch/。The newest version seems to be slower, so v6.8.6 was used. 
  For Perple_X, if using the default setting, it will prompt “**error ver041** too many pseudocompounds, routine: SUBDIV”. So the initial_resolution was reduced.

Reliability Of Results

In order to demonstrate the reliability of GeoPS, we recalculated several phase diagrams of various rock types which are generated by THERMOCALC in published articles. The results are consistent with that calculated by THERMOCALC while using the same thermodynamic dataset and Solution models.

P-T pseudosections of metamafic rocks in the NCKFMASHTO system

For melting metamafic rocks in the NCKFMASHTO system, the comparison using the FIG. 4a in Green et al., 2016 JMG. The same bulk composition and activity model are used. The result of GeoPS is identical to the original diagram, except in the lower-left corner. The result of GeoPS also is consistent with the results of THERIAK-DOMINO, although some assemblage boundaries are not smooth in the lower-left corner of this diagram.

P-T pseudosections of metapelites in MnNCKFMASHTO system

The left figure is the Fig.9 in White et al., 2014 JMG which is calculated by Thermocalc. The right one is calculated by GeoPS with the same dataset and a-x models as that of this paper.

P-T pseduosections of ultrabasic rocks in NCFMASOCR system

The left one is the Fig.1 of Jennings and Holland 2015 which is calculated by Thermocalc. The right one is calculated by GeoPS with the same dataset and a-x models of this paper.

No Costs Of Learning

User can easily use GeoPS to implement a phase equilibrium computing in a few minutes， even has no experience in phase equilibrium modelling. It is very easy to obtain the software. It can be directly opened or installed from this website's home page. After input of bulk composition, the phase diagram calculation can be completed automatically with one click. And the preliminary results during the calculation process will be displayed on the main interface in time.

Refference

Xiang, H., & Connolly, J. A. D. (2021). GeoPS: An interactive visual computing tool for thermodynamic modelling of phase equilibria. Journal of Metamorphic Geology,1–13. https://doi.org/10.1111/jmg.12626 PDF